Wash chicken. Take it in a pressure cooker and add 4 cups of cold water. Bring it to the boil. You will see some foam on the surface when it starts to boil. Take them all with a spoon and discard. Add black pepper. Close the lid of pressure cooker and turn the heat down to low. Cook the chicken for 15 minutes at low heat. Take the pressure cooker and let it cool. Open the lid when it is cool enough and take the chicken out in a plate leaving meat broth in the pressure cooker. Take the bones of chicken and cut them into small pieces.Add tomato and pepper paste into the pressure cooker. Stir and cook for 5 minutes. Add vermicelli and chicken in to the pot and bring it to the boil. Turn the heat down to low. Cover the lid and simmer it for 25 minutes and turn the heat off. Add salt. Let it rest for 10 minutes before serving.Serve it with lemon juice.